Starting device for sewing-machines



E. B. ALLEN. STARTING DEVICE FOR SEWING MACHINES,

APPLICATION FILED MAR. I9, I919.

Patented Mar. 23, 1920.

W W m 1 I m m 0 s f 7 M m 3 m L my A ORNEY E. B. ALLEN. STARTING DEVICE FOR SEWING MACHINES.

I APPLICATION FILED MAR. 19, 1919. 1,334,640.

lNVENTOR 2 SHEETS-SHEET 2 ATTORNEY Patented Mar. 23, 1920.

WITNESSES:

EDWARD B. ALLEN, 013 BBIIDG-EPURT, CONNECTTGUT, .ilfiSIGrlllUR TO THE SINGER MANU- FAG-TUBING- CUMPANY, A GORPORATTUN Ell-2 NEW JERSEY.

STARTING IJEVIGE FOR EBEVIING-IILVIAOI'IIIZI'ES.

Specification of Letters Patent.

Patented Mar. 23, 1920.

Application filed March 19, 1919. Serial No. 283,604.

To all whom it may concern Be it known that T, EDWARD B. ALLEN, a citizen of the llnited States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Starting Devices for Sewing-Machines, of which the following is a specification, referencebeing had therein to the accompanyingdrawings.

ln certain types of automatic sewing machines such as automatic buttonhole'cutting and stitching machines, it has been custo1nary to provide a handor finger-operated starting device for initiating a cycle of operations; said starting device including a linger-piece disposed adjacent the sewing point and in overhanging relation with the usual worleholder.

Since the stitch-forming mechanism of these machines comprises a vertically reciprocating needle which cooperates with a looper or other thread-handling implement mounted beneath the WOI'k-llOlClel, it is necessary in gaining access to the lower threadhandling implement, to shift the workholder to an abnormal position to uncover the space occupied by the said lower thread handling means.

Inasmuch as the linger-piece of the starting mechanism is, for the sake of convenience, located in close proximity to the sewing point, it often happens that an oper ator in adjusting or threading up the lower needle or looper, will accidentally touch the finger-piece and trip the machine into action at an inopportune time. Thus the operator is liable to be injured or the machine damaged.

An object of the present invention is to provide a finger releasing mechanism of such a nature that whenever the operator is obliged for any reason to shift the workclamp to an abnormal position, the finger release mechanism will be rendered inoperative to start the machine. i

Further objects of the invention will ap pear from the following description and claims.

According to the present improvement the linger-piece of the starting mechanism is mounted on the work-holder and is arranged so that a rearwardly extending portion thereof will transmit motion to a connection with the usual starting clutch of the machine. Thus, whenever the operator is obliged to shift the workholder, as when threading up the lower needle, or when adjusting any of the parts beneath the workholder, the rearwardly extending portion of the fingenpiece carried by the work-holder will be shifted beyond a position where it is operative to transmit motion to the starting clutch, l lfhen the work-holder is returned to normal position the finger-piece is necessarily restored to a position where it is operative to start the machine.

In the accompanying drawings, Figure 1 is a perspective view of the buttonhole sewing machine embodying the invention. Fig. 2 is a perspective view of one of the workclamping sections of the work-holder of the machine. Fig. 8 is a horizontal section through the standard of the machine, show ing the bed and work-holder in plan. Fig. 1 is a vertical transverse sectional view through the worli-clamping sections shown in 2.

ln the specific embodiment of the invention chosen for the purposes of the present disclosure, the machine frame comprises a hollow rectangular base 1, standard 2, bracket-arm 3 and head 1 in which is journaled a reciprocating needlebar 5 carrying the eye-pointed needle 6 which cooperates with a lower curved needle 7 in the usual manner disclosed in my Patent No. 1,162,207 to form overseaming stitches.

The work-holder of the machine is constructed substantially in accordance with the disclosure of my copending application Serial No. 180,737, filed July 16, 1917, and comprises separable clamping sections each of which consists of a lower work-supporting plate 8 and an upper clamping foot 9 pivotally connected at the free end of a ver tically movable clamping arm 10 which at its rearward end is pivotally mounted, as usual, upon the rearward end of the corresponding work-supporting plate 8. As illus' trated in Fig. 4, the upper clamping arm 10 is secured at its rearward end to a fulcrum block 11 fixed to the fulcrum-pin 12 journaled in the bracket 13 mounted upon the work-supporting plate 8.

The separable sections of the work-holder are carried by the usual carrier or cross slide-plate 14 having at its forward end the downwardly projecting lugs 15 which slidably embrace the usual cross-rod. 16 carried by and forming a part of a longitudinal slide-plate or slide-frame 1 6.

Secured to the upper side of the front end-portion of the carrier-plate 14 is the transversely extending retainer-plate 17, the straight rearward end of which is undercut to form an overhanging flange 18 which extends over the flanges l9-at the front ends of the separable clamp-plates 8. At their rear ends the clamp-plates S are held down upon the carrier 14 by means of suitable overhanging retainer-blocks 20 fixed to the longitudinal slide-frame 16. The retainerblocks 20 and retainer-plates l7 define a transverse slideway, outwardly of which the clamp-plates 8 may be shifted, as will be readily understood. The sections of the work-clamp are yieldingly maintained in normal operative position in the lateral slideway by means of the spring-pressed latch-levers 20 and the springs 20. The latch-levers 20 are fulcrumed at 20 to the carrier-plate 14, while the springs 2O are secured to the respective clamp-plates 8 and are formed with rearwardly projecting ends which bear outwardly against suitable abutments 2O fixed to the longitudinal slideplate 16.

Longitudinal and lateral traveling move ments may be imparted to the clamp-carrier plate 14 by suitable connections with the usual feed-wheel 21 such, for example, as represented in my pending application Serial No. 17,595, filed March 29, 1915. The feed-wheel 21 has cam-grooves 22 and 23 and respective lever-connections 24 and 25 for imparting longitudinal and lateral components of motion to the worlcholder.

As the particular machine illustrated is intended for sewing round eyelets, the lateral and longituoinal movements of the work-holder are so compounded as to shift the work-holder in a substantially circular path; the usual clamp-spreading mechanism being omitted. However, in the case of a machine intended for sewing buttonholes, the clampspreacling mechanism of my said copending, application Serial No. 180,737, may be employed.

Machines of the present type commonly embody automatic mechanism for cutting a hole or slit in the material preparatory to stitching. This mechanism commonly comprises upper and lower cutter-levers 26 and 27 respectively, pivotally mounted at 28 upon a traveling fulcrum block 29 and provided at their forward ends with the usual cooperating cutter and anvil elements, the former ofwhich is shown at 30, Fig. 1. The levers 26 and 27 extend, respectively, above and below the cutter-shaft 31 and are maintained in engagement with the cutter closing cams 32, 33 by means of the spring 34 anchored at its ends to the respective cutter-levers.

The cutter-levers are moved into and out of cutting relation with the work-holder by means of the usual cutter advancing and retracting cam 35 mounted on. the cuttershaft and connected by the follower link 2313 to the traveling fulcrum block 29.

The cutter-shaft 31 is adapted to be connected to the constantly running pulleywheel 37 through a well known one-revolution clutch device comprising a driven disk 38 fixed to the cutter-shaft and carrying an outwardly spring-pressed elutclrtooth ill adapted, when released, to be projected into engagement with one of the several peripherally disposed and inwardly directed driving shoulders 40 on the driving disk 41, as represented in my Patent No. 1,024,490, of April 30, 1912.

The clutch-tooth 39 is controlled by the flanged extremity 42 of the clutclrcontroh ling bellcrank-lever 43, 44, fulcrumed upon the bed 1 at 45 and normally held in clutchdisengaging position, Fig. 3, by the coiled spring 46 secured at one end to the arm 4-4 and at its opposite end connected to the standard 2 at 47.

As this type of clutch mechanism is well known, further description of the details thereof is believed to be unnecessary. It will sufiice to point out that when the operator shifts the flanged extremity 42 of the lever 43 inwardly toward the standard 2. the clutch-tooth 39 is released and is then projected into engagement with the driving disk 41 for a single rotation, after which the clutch-tooth is withdrawn from the driving disk by the cam-shaped inner edge (not shown) of the flange 42.

It is further generally understood by those familiar with machines of this type that the sewing mechanism, which is stationary during the operation of the buttonhole cutting mechanism is provided with a stop-motion s such as represented in my- Patent No. 1,240,642, which stop-motion has automatically tripped into action by the cut ting mechanism after the button-hole has been cut, so that all the operator has to do is to trip the cutter-shaft into operation whereupon the machine will operate auto matically to cut and stitch the buttonhole.

In accordance with the present invention, a finger-lever 48, having its forward extremity 49 disposed conveniently near to the stitching point, is pivotally carried by one of the separable sections of the work-clamp and is so connected to the clutch-controlling lever 43, 44, that when the operator shifts the clamp-sections outwardly to abnormal position to expose the lower sewing instrumentalities for adjustment or threading, the train of operative connections between the finger-lever L8 and the clutch-controlling lever 48, dd, will be interrupted, whereby the linger-lever becomes inoperative to start the machine.

The finger-lever 48, Fig. 4, is loosely fulcrumed intermediate its ends upon an outward extension of the fulcrum-pin 12 for the left-hand work-clamping arm 10 of the machine and is yieldingly held with its forward end elevated by a coiled spring surrounding the fulcrum-pin 12. At its rearward end the finger-lever carries a wearpiece 51 which extends under the inwardly bent extremity 52 of the forwardly extend ing arm 53 of a bellcrank-lever fulcrumed upon the standard 2 at 54: and having its upstanding arm 55 freely connected to the front end of a rod 56 which at its rearward end is connected to the extremity of the arm a l of the clutch-controlling bellcrank-lever.

Nhen the sections of the work-clamp are in normal or operative position, Fig. 3, pres; sure upon the button 4-9 will act through the train of connections above described to withdraw the flange 4-2 from the clutch-tooth 39 and start the machine. It will be observed, however, that by virtue of the mounting of the fingerrelease button e9, upon one of the separable sections of the work-clamp, and by virtue of the necessity of shifting said section of the work-clamp outwardly or removing it from the machine to expose the instrumentalities therebelow, the operator may, with security, thread up the lower needle or adjust the looper mechanism or other parts beneath the work-clamp, without the necessity of having to remember to shift a safety device or take any other such voluntary action as heretofore commonly required to forestall injury to himself or to the machine.

While I have shown and described one specific embodiment of the invention, it is to be understood that the invention is not limited to the details of the construction disclosed herein. Various substitutions, modifications, rearrangements, additions, omissions, and the like, will be obvious to those skilled in the art, in the light of the present disclosure.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, in combination, stitch-forming mechanism, means for controlling its period of action, a work-holder manually shiftable when the machine is stationary to expose parts of the machine adjacent the sewing point, and a finger-re1ease mounted on said work-holder and rendered inoperative to start the machine by movement of the work-holder to abnormal position.

2. In a sewing machine, the combination with stitch-forming mechanism, means for controlling its period of action, a work holder shiftable from normal to abnormal position, and feeding mechanism for normally producing relative movement between the stitch-forming mechanism and workholder in the production of a stitched figure, of means for starting the machine including a manually operable finger-piece mounted on the work-holder and shiftable with the latter to abnormal position wherein said finger-piece is, inoperative to start the machine.

3. In an automatic buttonholecutting and stitching machine, the combination with stitch-forming mechanism, a worlcholder including separable sections each comprising a work-clamping plate and an upper clamping foot, buttonhole cutting mecha nism, means controlled by one of said mechanisms for automatically starting the other mechanism, and a manually controlled starting device for said one of said mechanisms, said starting device including a finger-release element mounted on one of the separable sections of the work-clamp and adapted to move to ineffective position when said section of the work-clamp is shifted to expose parts of the machine therebelow.

4. In an automatic sewing machine adapted to perform a predetermined cycle of operations and then come to rest, the combination with upper and lower stitch-forming instrumentalities, a work-clamp, a starting clutch and starting connections therewith, of a finger-release mounted on said worlcclamp and normally in position to actuate said starting connections, there being a loose connection between said finger-re lease and said starting connections, whereby when the work-clamp is shifted manually to permit threading of the lower stitch forming instrumentalities the finger-release is necessarily rendered inoperative.

In testimony whereof I have signed my name to this, specification.

EDWARD B. ALLEN. 

